(1) Field of the Invention
This invention relates to disposal of slaughterhouse waste liquids, and more particularly to a gravitational separation of the oils and tallow to the top and heavier solids to the bottom, with cleansed water drawn off from in between.
Applicant submits that a slaughterhouse operator is one having ordinary skill in this art. Applicant believes this application to be in the field of liquid separation.
(2) Description of the Related Art
This invention is an improvement for the equipment disclosed in my prior U.S. Pat. No. 3,947,355; issued Mar. 30, 1976. That patent discloses a separator tank. The tank has a cylindrical container with a vertical axis. The inlet material is fed to the tank in a quiescent zone about midpoint between a liquid surface level at the top and a solid waste sump at the bottom. The cleansed water is removed from the quiescent zone which is the zone between the liquid surface level at the top and the sump at the bottom.
In operation, the flow into the separator is about 1,000 gallons per minute. Most of the outlet from the separator is the cleansed water, which therefore also has a flow rate of about 1,000 gallons per minute. The rest of the outlet is the water, tallow, and oil that is skimmed from the top and the water used to flush the solids from the sump.
Operations show that there is difficulty withdrawing water at this flow rate from the quiescent zone without disturbing or stirring up the liquid at the quiescent zone. I.e., the flow rates are so large that it inherently causes turbulence of the water; therefore, causing a certain amount of tallow, oils, and solids to be withdrawn at the water outlet.